A Killer Takes Wing

For the avian flu to reach North America -- and there is no known way to stop it -- all it will take is an infected bird's migration.

FAIRBANKS, Alaska — Beneath a dim morning sky, Jonathan Runstadler trudged across the ice with a long fiberglass tube, some gardening tools and a smattering of plastic lab bottles.

Months earlier, summer breezes had carried wild birds from Asia to this little pond. Now, with the temperature hovering at 9 degrees, Runstadler bored through the frozen surface in search of the seeds of a pandemic.

"Ground Zero is what's in birds," said the University of Alaska molecular biologist, who dropped hockey puck-shaped ice samples into a Ziploc bag.

This snowy patch of the Alaskan wilderness sits at the edge of a bird flu outbreak that emerged in Hong Kong in 1997 and has recently spread as far as Kazakhstan, Croatia and Siberia. The virus has ravaged farms in Thailand and felled wild birds from western China to Eastern Europe.

For The Record Los Angeles Times Saturday January 14, 2006 Home Edition Main News Part A Page 2 National Desk 1 inches; 67 words Type of Material: Correction Bird flu -- A front-page article Tuesday about avian influenza said 8 million Spaniards died from a virulent flu strain in May 1918. The number was based on a 1918 report in the British Medical Journal that was never substantiated. The true figure is unknown, but modern estimates place the death toll from the so-called Spanish flu that year at as many as 50 million people worldwide.

Turkey has become the latest hot spot, reporting at least two human deaths from bird flu since the start of the year -- the first human cases outside Asia.

Since 2003, the virus has killed 76 people in its march across the globe, according to the World Health Organization. More than half died in the last year.

What Americans once viewed as a distant scourge is now just across the Bering Strait. If it arrives in North America, scientists expect to find it first in Alaska, a breeding ground for many migratory birds from Asia.

The bird flu virus, known as H5N1, is the culmination of random mutations and countless viral mixings, producing a strain of influenza completely unfamiliar to the human immune system.

It could be just a few more mutations away from being able to easily infect and spread among people -- the raw ingredients needed to spark a global pandemic. Or it could evolve into a harmless strain.

Its future is uncertain.

The virus is not so different from the common flu that causes fevers and runny noses each winter. Yet it has provoked a degree of fear that belies its mundane origins.

Governments have slaughtered millions of chickens and other poultry. Hospitals are stockpiling Tamiflu and other antiviral medications. Scientists are racing to develop a vaccine.

In Alaska, scientists such as Runstadler are searching for traces of H5N1 in bird droppings left from the summer breeding season. They could be preserved in now-frozen water or soil.

"It's just a matter of time before H5N1 shows up everywhere," said George M. Happ, a biologist at the University of Alaska who is coordinating the state's pursuit of the virus.

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It arrived with little fanfare.

In May 1997, there was panic in Hong Kong over an outbreak of German measles that sickened more than 1,500 people, mostly teenagers.

Amid the commotion, a 3-year-old boy with fever, aches and a sore throat was admitted to a Kowloon hospital. He had typical flu symptoms, nothing unusual in a young child.

Yet as the days progressed, the boy's illness continued to worsen. His symptoms indicated viral pneumonia and Reye's syndrome, a rare disorder that causes brain inflammation.

He died six days after being admitted to the hospital.

Dr. Wilina Lim, a virologist with Hong Kong's Department of Health, tested a fluid sample from the boy's windpipe.

It was a puzzle. She confirmed it was an influenza virus but couldn't identify it.

Lim sent off samples to two of the top infectious disease laboratories in the world -- the U.S. Centers for Disease Control and Prevention in Atlanta and the National Influenza Centre in the Netherlands.

Three months later, she received a startling reply: The boy had been infected with a virus that had been found only in birds.

Kennedy Shortridge, a University of Hong Kong microbiologist, had identified a nearly identical virus a few months earlier as the cause of 4,500 chickens' deaths on farms in Hong Kong's Yuen Long district.

To the virologists on the case, the notion that bird flu could kill humans was preposterous.

At first, they suspected the samples had been contaminated by virus particles from Shortridge's lab. Only after ruling out that possibility did they realize the significance of the discovery.

It was the first documented case of bird flu jumping directly to humans with lethal consequences.

New patients came down with H5N1 in November 1997. All but one had visited Hong Kong's live poultry markets within several days of the onset of their symptoms.

Altogether, 18 people came down with severe respiratory illness. Six of them died.

Because the outbreak coincided with the onset of the regular flu season, health officials worried that H5N1 could mix with a human flu strain and morph into an easily transmissible virus.

Hong Kong's health director, Margaret Chan, ordered the culling of all poultry in the territory.

Secretaries, park rangers and dog catchers were drafted to help slaughter 1.6 million chickens, ducks, quails, partridges and geese. Workers in white suits and masks hauled the carcasses to a landfill.